Re: [boost] shared_ptr / auto_ptr

From: Daniel Frey (d.frey_at_[hidden])
Date: 2008-03-21 11:42:40

On Fri, 2008-03-21 at 16:30 +0200, Peter Dimov wrote:
> Daniel Frey:
> 
> > is there any reason why shared_ptr does not have a ctor that takes an
> > auto_ptr and a deleter?
> 
> shared_ptr assumes that an object that is owned by an auto_ptr needs to be 
> destroyed by delete, because that is what the auto_ptr would do if, for 
> example, an exception is thrown before the line that transfers the ownership 
> to a shared_ptr.

In my scenario, the deleter tries to store the object in a pool instead
of deleting it. From that pool, it will later be either reused or
actually deleted. Since I'm just deferring the 'delete', it's fine when
auto_ptr does it immediately in case of exceptions.

> > I also wonder if there is a resource leak if I just write:
> >
> > auto_ptr<T> a = ...;
> > my_deleter d = ...;
> >
> > shared_ptr<T> s( a.release(), d );
> 
> No, there isn't. 

Good to know. As long as this works, the missing ctor is no big deal for
me. Thanks.

Regards, Daniel